They're hugely popular amongst auto enthusiasts. Not only do "race shops" sell crate engines, but most OEM's sell them too. For example, here are Chevy's offeri

They're hugely popular amongst auto enthusiasts. Not only do "race shops" sell crate engines, but most OEM's sell them too. For example, here are Chevy's offerings. https://www.chevrolet.com/performance/crate-engines https://www.chevrolet.com/performance/crate-engines